There is no scientific records of snakeheads destroying natural habitats because from my knowledge they have been contained until several years ago. Personally I think snakeheads could do more harm then good, the only fish that can compete with them in the south would be large catfish and full grown largemouth bass. Snakeheads get larger than bass and larger than what a catfish could eat. With no predators and profilic breeding fish they will most likely outcompete and eat most native fish. Recipe for disaster.